Hello to all.I'm looking for a script that compares the number of files in two directories that I'll give as an input and prints the result of this comparison.I know it may seem easy,but I'm a newbie and in need of your help.Thanks in advance.

Sounds like a homework, so I shall not give you a direct answer. Programs / things you might find useful:

• The program ls
• The program wc
• How to compare numbers in shell scripts. Check out the "CONDITIONAL EXPRESSIONS" section of the bash manual page.

Tell us what you tried, and we will correct you and point you in the right direction.

Here is the script I've written,but it has some errors.

#!/bin/bash
echo "give the names of the 2 direcories"
read NAME1
read NAME2
cd $NAME1
ls|wc -l>file1
cp file1 ~
cd ..
cd $NAME2
ls|wc -l>file2
cp file2 ~
cd ..
x=tail +1 file1
y=tail +1 file2
if ($x>$y); then
echo "first directory has more files"
else if ($x=$y); then
echo "direcories have the same number of files"
else
echo "second directory has more files"
fi
fi

My problem now is in the fact that this script works for the correct number only the first time,for the rest compares one more file for each directory.Furthermore,I can't store the first line of the files to a variable for the comparison...thanks for the advices matthewg42

You can put shell script and other source code in [code] tags and it will look a lot better - for example, indentation is preserved.

A few observations which should help:

• bash's read command can prompt for you, so you don't need to do an echo first. For example:
  
  Code:

  read -p "enter a directory: " NAME1

• there's no need to re-direct the output of wc into a file. You can read it directly into a variable like this:
  
  Code:

  count=$(ls |wc -l)

  This is true for any command which produces output on the standard output file descriptor (i.e. most of them), although you should probably not do this when the output of the command could be a very large amount of data
• Try "[" and "]" instead of "(" and ")" in the "if" part. Note that you need spaces between the "[" and "]" and each operand / operator.
• The integer equality operator is "-eq", not "=", although "=" should work, because it is string comparison.

Thanks again for your answer matthewg42.Your advices are very helpful.Here is a second the script :


My problem now is that for every combination of directories every time prints first directory has more files.Where are my mistakes..?
Thanks in advance...

After doing "cd [some directory]", you can do "cd -" to return to the previous directory. Consider when NAME1 is something like "directory/subdirectory" - the "cd .." will not return to the original directory, but "cd -" will.

In fact, you don't really need to change directory at all... you can do:
ls will output the contents of "dirname" if it is a directory, so you can assign your variables simply like this:
The greater than operator is -gt (-lt is less than, -ge is greater than or equal to, and so you can probably guess what -le is). In shellscript the ">" character re-directs the output of the statement to the left of the character into the file to the right of it. You will probably have some files whose names are numbers after running your script

Use "elif" not, "else if". Why every language on the planet has to invent a new way to say "else if" I do not know, but heh.

Use [code] tags, not [quote] tags when posting code. It looks much better (fixed width font, preserved whitespace).

Now my script looks like this..:
But the problem remains.I always get that the first directory has more files,even if it's not true.Thanks for all your tips..They help me with other scripts as well.

You should quote both sides of the operands in the if statement (or neither side), i.e.

Thanks for all your help matthewg42.You 've been very helpful.The script now works like a charm and is exactly what I need.
Thanks and again thanks...